Indoor positioning systems are widely used to locate objects and people in indoor environments. As global navigation satellite systems (GPS or GNSS) are generally not suitable for indoor locations, various techniques relying on wireless infrastructure installed indoors have been developed. For example, Wi-Fi positioning systems include wireless access points (APs) distributed throughout an indoor facility and employ maps of received signal strength (RSS) fingerprints for location determinations. Other techniques based on Bluetooth and radio frequency identification (RFID) technologies can be found in commercial implementations of indoor positioning systems.
Accurate indoor localization can facilitate navigation in indoor environments. In particular, where the structural layout (e.g. two- or three-dimensional maps) of an indoor facility can be obtained, positioning information can be combined with structural details of the facility to provide navigation or routing information. For example, a mobile device capable of implementing indoor localization may allow transitioning from navigating outdoors (e.g. via use of GPS) to navigating inside a building.
Indoor positioning systems often require installing additional hardware infrastructure, which can be expensive and cumbersome. A lightweight method for navigating using a mobile device would be desirable.
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